1. Field of the Invention
The present invention relates to a cutting tool set for cutting paper or sheet webs, particularly for cutting off product packings by successive cutting through cross sealed areas of a tubular packing material with enclosed products such as edible ice bodies, comprising a knife with a sharp edge and means for pressing the knife against an anvil for cutting through an intermediate web.
2. Description of Related Art
In so-called flow packing systems, e.g. for packaging of ice lollies, the products are supplied with mutual spacing to an advanced paper or sheet web, which is currently folded about the products to form a tubular wrapping, this being currently closed by a length sealing and by cross sealing in the areas between the products. At the discharge end of the line a cutting of the web is effected through the cross sealed areas for successive separation of individual packings.
Normally, this cutting is effected by means of a knife and a backing anvil mounted on opposed rotary shafts, between which the sheet web is advanced. During the rotation the knife is forced against the anvil, whereby the web is cut. The knife may have a straight or an undulated cutting edge. The knife and/or the the anvil may be supported resiliently in the radial direction.
For achieving a safe cutting operation the knife should be positioned relative to the anvil with regard being had to the type and dimension of the web to be cut. Also, the pressure between the knife and the anvil should be adapted to this positioning and the said web conditions. If the pressure is too weak the knife may not cut the web entirely, e.g. leaving fibres in the cutting line uncut. On the other hand, if the cutting pressure is too high the cutting edge will be pressed flat, whereby the cutting ability is reduced. In order to counteract such a wear the knife and the anvil may be arranged resiliently relative to each other, but still it is difficult to ensure both an efficient cutting and a long lifetime of the knife. It is necessary to adjust the positions of the knife and the anvil very precisely for securing a safe cutting operation.
However, such an adjustment can be very time-consuming and troublesome, and on this background it is the purpose of the present invention to provide a cutting arrangement that will protect the cutting edge against deformtion and is easily adjustable to a desired pressure between the knife and the anvil.